Thursday, August 10, 2017

On the Climate Change Front - Sea Level Rise and Forest-Killing Drought

It's been known for some time that sea level rise is worse in some areas than in others. America's eastern seaboard is one example. Now, a study out of the University of Florida examines the development of "hot spots" on the eastern coast, places where seas levels have risen more than six times the global average.

What they've found is that climate change is just a contributing factor that is compounded by other variables primarily El Nino and the North Atlantic Oscillation.

The findings -- detailed this week in the journal Geophysical Research Letters-- contradict the theory that recent sea level rise was triggered by a slowdown of circulation in the North Atlantic, a phenomenon blamed on global warming.

Scientists aren't ignoring the risks of man-made global warming. Instead, the authors of the new study suggest their work highlights the regional dangers of global sea level rise.

"It's amazing to see construction along the East Coast. That's the worst place to build anything," said Arnoldo Valle-Levinson, professor of civil and coastal engineering sciences at Florida. "We need to understand that the ocean is coming."

Meanwhile very heavy rains over a short interval that caused flooding across Yorkshire and Lincolnshire over the past few days are drawing attention to a little discussed problem - resilience. How many times can buildings, especially old, historic structures, sustain flooding before they're no longer structurally viable? These buildings were constructed to meet a climate that is no longer, a milder and gentler environment.

When it comes to resilience, climate change can be resemble a prize fighter. It's never the ability of the boxer to take a punch that matters. It's the fighter's ability to weather a succession of punches and remain standing at the end of the match. This is as much a concern when it comes to serial droughts as for serial flooding.

Trees and their environment need as long as two years to recover from drought in some places, and if a second dry spell hits before then, it may cause permanent damage to the landscape, researchers said on Wednesday.

With climate change expected to bring more frequent and intense droughts, the implications for areas that do not have time to bounce back fully could be severe, the researchers said in a paper to be published in Nature journal this week.

"That could have a double whammy effect," said co-author William Anderegg, assistant professor of biology at the University of Utah. "A second drought could be harder on an ecosystem and have the potential to push it off a cliff."

The Amazon rainforest, considered the terrestrial "lungs of the planet" is now enduring its third, once-in-a-century drought, in the span of just the past 13 years. Three droughts that, in the previous climate, would have taken 300 years to manifest, now hammer the rainforest in just 13 years. Not much of an optimism builder, is it? 

How much more will the Amazon be able to take? And what about the human hand in this, illegal deforestation that occurs while governments look the other way? The Amazon not only provides a massive source of oxygen, its humidity also provides the precipitation that creates the freshwater source for major cities such as Sao Paulo, a mega city of over 12-million.

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